Principles Underlying the Draft of the Horse. 497 



between the two horses so long as the evener crosses the 

 line of draft at a right angle, but as soon as one horse falls 

 behind the other then only the third type remains a just 

 equalizer. The truth of this statement can be readily 

 demonstrated with the apparatus represented in Fig. 237, 

 where the three types of eveners are combined in one piece. 



FIG. 237. -Apparatus for demonstrating the principle of eveners 



Referring to the figure it will be seen that as the clevises 

 for the whiffletrees are there set the evener may be made 

 to form various angles with the line of draft and the in- 

 equality of draft resulting may be measured with the pair 

 of scales. With a 4-foot evener where the holes for the 

 clevises are 4 inches behind the draft pin the horse which 

 is ahead may have an advantage greater than 25 per cent., 

 if the angle formed is as much as 20. 



